Development of High-Tg Reprocessable Vitrimers through Molecular Rigidity Control of Bismaleimide Monomers

Thermosetting resins are high-performance polymeric materials with high glass transition temperatures, excellent thermal stability, mechanical strength, and dimensional stability. However, their permanent crosslinked networks make reprocessing and recycling difficult, raising sustainability concerns. Covalent adaptable networks based on dynamic covalent bonds have been explored to address this issue, but they often exhibit reduced glass transition temperatures, thermal stability, and mechanical strength because of reactive functional groups and flexible network structures. In this study, a novel bismaleimide-based monomer was designed and incorporated into a thermosetting polymer network to provide both dynamic covalent bonding and structural rigidity. The resulting thermoset showed a glass transition temperature above 300 °C and thermal stability above 400 °C. It could also be reprocessed multiple times while retaining excellent thermal and mechanical properties.